This invention relates to an apparatus integrated in a fiber processing machine, such as a spinning preparation machine or a spinning preparation line for recognizing and processing impurities, foreign bodies and foreign fibers in textile fiber material. The apparatus has at least two light sources which illuminate the fiber material alternatingly with different colors and further, a sensor is provided which detects the colors of the light after it impinges on the fiber material. An electric signal is generated if an abrupt color change of the fiber material from a predetermined color occurs.
European Patent 0 399 945 discloses an apparatus in which one or several two-color (red and green) LED light sources are provided for alternatingly emitting red and green (thus, narrow-band) light. It is a disadvantage of this prior art arrangement that the colors may not be adapted to the prevailing needs, since only red and green lights are alternatingly emitted. It is a particular drawback that with one light diode neither a light of another color, for example, white, yellow or blue color nor a color mixture may be generated and emitted.
It is an object of the invention to provide an improved apparatus of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, adapts the light colors to the application at hand, for example, to different or varying colors of the fiber material.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for detecting foreign bodies in fiber material includes at least two light sources. At least one of the light sources has at least three light emitting elements. Each light emitting element radiates a light of different color. An arrangement directs the light emitted by the light sources to the fiber material for illuminating the fiber material, and a sensor detects the illuminating light after illumination of the fiber material for emitting an electric signal upon a sudden color change of the fiber material. An arrangement causes the light sources to alternatingly illuminate the fiber material with different colors, and further, an arrangement selects the color emitted by the light sources as a function of the color of the fiber material.
The multi-colored light source, particularly a multi-colored light diode, provides that by means of a single structural element the generation and emission of a plurality of colors with a minimum spatial requirement may be achieved. The universal light color generation may be effected by means of a simple electric control circuit. By selecting a color or colors from a large spectrum, an illumination with an individual, application-specific light color is possible.
The invention has the following additional advantageous features:
The colors are variable.
The multi-colored light source is connected to a control device which determines the particular color or color combination with which the multi-colored light source illuminates.
The multi-colored light source may illuminate simultaneously with more than one color.
The multi-colored light source may illuminate alternatingly with more than one color.
The multi-colored light source is a multi-colored light diode.
The multi-colored light source may produce light in a large frequency range.
Light flashes of different color may be generated sequentially and at short intervals.
The sensor is a camera which produces an image for each individual light flash.
Particular colors emitted by the light source may be selected for the light flash as a function of the fiber material to be examined.
The colors with which the light source illuminates are individually determinable.
The light source may be used essentially with a single color (standard color) and, dependent on image evaluation, with at least one further color.
The standard color may be set manually based on an optical impression or it may be set automatically, for example, by means of a color measuring sensor which is coupled electrically with the image processing system, for example, by means of a data interface.
The standard color may be set continuously based on the measuring magnitude of the color measuring sensor.
The color measuring sensor is associated with a fiber processing machine, such as a bale opener.
A position measuring device for the tuft removing mechanism of the bale opener is coupled to the image processing system.
A multi-colored light source is utilized.
At least one multi-colored illuminating element (diode) is coupled to an electronic image data processing device.
The multi-colored illuminating system may emit light of different colors as a function of control.
The color or colors of the multi-colored light source are variable.